In general, in a wafer polishing process, in polishing which is performed immediately after attachment of a polishing pad to a polishing machine, generation of a scratch on a wafer or significant degradation of the particle level is sometimes observed. Furthermore, the larger the polishing machine becomes, the more likely the generation of a scratch or degradation of the particle level is to occur. It is considered that the generation of a scratch and degradation of the particle level occur due to an insufficient rise of the just-attached polishing pad.
In raising the polishing pad, dressing is generally performed by using a dresser or the like with a surface covered with diamonds as described in Patent Document 1 in order to adjust the surface roughness or thickness of the polishing pad. However, even when the polishing pad is raised by such dressing, degradation of the particle level is observed immediately after the start of polishing (hereinafter also referred to as the “polishing pad life early stage”), which makes it clear that dressing alone results in an insufficient rise of the polishing pad.